染发类产品Ames试验中不同剂量下细菌毒性和培养时间的探讨

Exploration on bacterial toxicity and culture time under different doses in Ames test of hair dye products

目的对染发类产品Ames试验中常见若干问题进行探讨,以期更加科学合理地判断受试物的致突变性。方法选取3种(A、B、C)染发产品进行Ames实验,检测其致突变性,比较肉眼和低倍显微镜(100×)对不同情况背景菌苔的观察结果;比较不同培养时间对于自发回变率低的TA98菌株试验结果的影响;通过调整剂量设计对可疑结果进行复测。结果试验条件下,随着A染发产品细菌毒性的增加,肉眼和镜下均可观察到TA98菌株背景菌出现渐变规律,在1 000μg/皿增加到4 000μg/皿细菌毒性范围内仍可有效区分背景菌与回变菌落;B染发产品培养时间延长至72h后,TA98菌株试验结果由阳性变为阴性;C染发产品缩小剂量间隔复测后,TA97a菌株试验结果由阴性变为阳性。结论染发类产品进行Ames试验时,不能简单地以2倍的标准来评判。

Objective To explore some of the most common problems in the Ames test of hair dye products in laboratory evaluation;to judge the mutagenicity of the tested substance more scientifically and reasonably.Methods Three kinds of hair dye products A,B and C were selected to conduct mutagenicity evaluation by Ames test,the observation results of background colonies under different conditions were compared by naked eye and low resolution microscope(100×);the effects of different culture time on the test results of TA98 strains with low spontaneous reversion frequency were compared;the suspicious results were retested by adjusting the dose setting.Results Under the experimental conditions,with the increase of bacterial toxicity of hair dye product A,the gradual change of background bacteria colonies of TA98 strain could be observed by naked eyes and microscope.The background bacteria and revertant colonies could be effectively distinguished when the bacterial toxicity from 1 000μg/plate to 4 000μg/plate;When the incubation time of hair dye product B was prolonged to 72 h,the test result of TA98 strain changed from positive to negative;after the retest of reduced dose interval of hair dye product C,the test result of TA97 astrain changed from negative to positive.Conclusion The mutagenicity of hair products evaluation by Ames test could not be judged simply by 2 fold standard.